Ultra-Low Petroleum Plastics

ABSTRACT

Plastic-like compositions having ultra-low contents of petroleum derived materials are provided. The materials comprise up to about 80% by weight of an inorganic salt having an average particle size between about 0.001 and about 300 μm and a plastic binder. The compositions have a low propensity to ignite or smoke in the presence of heat or flame.

FIELD OF INVENTION

The present invention relates generally to plastic-like materials havingdiminished contents of petroleum-derived products. The invention alsorelates to fire retardant plastic-like materials.

BACKGROUND OF THE INVENTION

Conventional plastic materials comprise synthetic polymers derivedpredominately from petroleum. The disadvantages of suchpetroleum-derived products are well known and include, for example, therapid depletion of the world's petroleum reserves, the deleteriousenvironmental consequences resulting from the poor biodegradability ofpetroleum-derived plastic materials, and the fluctuating cost of plasticproduction with the price of oil. Even conventional “low petroleum”plastics such as polyvinyl chloride (“PVC”), which comprisesapproximately 43% by weight petroleum feedstock products, suffer fromthese disadvantages.

Accordingly, it has long been desirable to decrease the petroleumcontent of plastic products. Unfortunately, satisfactory alternatives topetroleum-derived plastic materials have not heretofore beencommercially viable. Therefore, there is a need in the art for plasticor plastic-like materials which have a reduced petroleum content ascompared to conventional plastics.

It is therefore an object of the present invention to provideplastic-like materials having a reduced content of petroleumderivatives.

It is further an object of the present invention to provide plastic-likematerials having chemical properties, such as fire retardancy and smokesuppression, superior to conventional plastics.

It is also an object of the present invention to provide materialshaving a reduced content of petroleum derivatives which are economicallyviable or superior alternatives to conventional plastics.

SUMMARY OF THE INVENTION

In accordance with the foregoing objectives and others, the presentinvention provides plastic-like materials having interesting physicaland mechanical properties, chemical properties such as fire retardancyand smoke suppression superior to conventional plastics, and diminishedpetroleum-derived material content as compared to conventional plastics.

It has surprisingly been found that plastic-like materials comprisingbetween about 20 to about 80% by weight of an inorganic salt can beobtained which have physical, mechanical, and chemical properties thatare useful for many of the applications in which conventional plasticsare employed. Some properties, such as fire retardancy, smokesuppression, toxicity of smoke release, and heat resistance aresubstantially improved as compared to conventional plastics.Importantly, the plastic-like materials or the invention are cheaper toproduce than conventional plastics.

In one aspect of the present invention a plastic-like composition isprovided comprising about 10% to about 80% by weight of a plasticpolymer and about 20% to about 80% by weight of an inorganic salt inparticulate form. In an interesting aspect of the invention, the weightpercentage of inorganic salt is above 50% and tends toward the upperlimit of the given range. The composition has a reduced propensity toignite or smoke in the presence of heat or flame as compared to thethermoplastic polymer which it comprises. The polymer may be either athermoplastic polymer or a thermosetting polymer. In one embodiment theplastic is a thermosetting plastic such as, for example, an epoxy resin.In another embodiment, the plastic polymer is a thermoplastic polymersuch as, for example, a polyvinyl, polyacrylate, polyurethane,polycarbonate, polyester, polyamide, or polyolefin polymer, or anycombination thereof. The inorganic salt according to one embodiment is asalt of phosphoric acid or sulfuric acid and in particular an ammoniumsalt of those acids. In another aspect of the invention, the inorganicsalt is provided having a relatively small particle size, such as, forexample between about 0.001 μm to about 1,000 μm. Within this range, ithas been found to be desirable to provide inorganic salts with particlesizes tending toward the lower limit.

These and other aspects of the invention will be better understood byreference to the following detailed description of the invention.

DETAILED DESCRIPTION OF THE INVENTION

Unless expressly defined otherwise herein, all terms are intended tohave their ordinary meaning in the art. As used herein, the term“plastic-like” refers to a material which comprises less polymericmaterial than conventional plastics but is nonetheless capable of beingmolded or formed with the application of heat or pressure in the samemanner as a conventional plastic material. The “plastic-like” materialsof the present invention share many of the physical and mechanicalproperties of conventional plastics, i.e., they may be shaped using anyof the conventional techniques useful for shaping conventional plastics,including for example, injection molding and rolling. However, theplastic-like compositions of the invention comprise far less polymericmaterial than conventional plastics.

The term “particulate form” is mean to expansively include any form ofsolid ammonium sulfate including but not limited to, crystallineparticles, microcrystalline particles, micronized particles,nanoparticles, amorphous particles, and the like. The term“thermoplastic” is meant to have its ordinary meaning in the art andgenerally refers to plastics which are capable of repeatedly softeningwhen heated and hardening when cooled. The term “thermosetting” is alsomeant to have its ordinary meaning in the art and generally refers toplastics which cannot be re-melted after being formed.

In the broadest embodiment of the invention, the plastic-likecomposition comprises about 10% to about 80% by weight of a plasticpolymer and about 20% to about 80% by weight of an inorganic salt inparticulate form. The composition has a reduced propensity to ignite orsmoke in the presence of heat or flame as compared to the plasticpolymer, alone. In certain embodiments, the composition is non-flammablewhen subjected to flame testing, such as U.S. Government standard forflammability resistance FAR 25.853(b).

An essential component of the composition is a plastic polymer. Theplastic polymeric component of the present invention may be any plastic(i.e., a thermoplastic or a thermosetting). In one embodiment, theplastic is a thermoplastic polymer. With due regard to the typicalcommercial thermoplastic polymers, particular mention may be made,without intending to limit the invention, to acrylics, such aspolymethyl methacrylate (PMMA), acryl-nitrite butadiene styrene (ABS),high density polyethylene (HDPE), low density polyethylene (LDPE),polycarbonates, polyesters, including polybutylene terephthalate (PBT)and polyethylene terephthalate (PET), polyamides, such as nylon,polyolefins, including but not limited to polyethylene andpolypropylene, polyorganosiloxane rubber, polytetrafluoroethylene(PTFE), polystyrene (PS), silicone polymers and copolymers,styrene-acrylonitrile (SAN), vinyl plastics, including but not limitedto vinyl acetate, polyvinyl chloride (PVC), chlorinated polyvinylchloride (CPVC), and polymers and copolymers of vinyl alcohol (VOH),polyurethanes, and polyvinylidene chloride (PVDC). Cellulosics,polyamideimide (PAI), polyarylate (PAR), polyetherimide (PEI),poly(phenylene sulfide) (PPS), polysulfone, polyethersulfone (PES),polyurea, polyetherketone (PEK), and polyetheretherketone (PEEK) arealso contemplated to be useful in the practice of the invention.

Particularly interesting thermoplastic polymers are those formed bypolymerization of vinyl monomers, including, but not limited to olefinicmonomers such as, for example, ethylene, propylene, 1-butene, 1-pentene,1-hexene, 1-heptene, 1-octene, 1-nonene, 1-decene, and4-methyl-1-pentene, wherein the alkyl substituents may be either linearor branched or may be cycloalkyl constituents. Vinyl aromatic monomerssuch as styrene and other aryl or hetero-aryl substituted vinyl monomersare also suitable. Exemplary styrenic monomers include styrene,α-methylstyrene, p-tertiary butylstyrene, p-methylstyrene,o-methylstyrene, m-methylstyrene, 2,4-dimethylstyrene, ethylstyrene,α-methyl-p-methyl styrene, bromostyrene, and the like.

Specific examples of homopolymers and copolymers of olefinic monomersare disclosed in U.S. Pat. No. 6,890,991 to Fujimoto et al, thedisclosure of which is hereby incorporated by reference, and include lowdensity polyethylene, ultra-low-density polyethylene, ultra-super-lowdensity polyethylene, linear low density polyethylene, high densitypolyethylene, ultrahigh molecular weight polyethylene, polypropylene,ethylene-propylene copolymer, polymethylpentene, polybutene, and thelike.

The vinyl monomers may also be vinyl halides. Desirable halogensubstituents are chlorine, bromine, fluorine or combinations thereof. Apreferred halogen is chlorine as in the case of the vinyl chloridemonomer. In that regard, polyvinyl chloride (“PVC”) is a particularlynotable plastic for use in the present invention. Other halogenatedmonomers include without limitation vinylidene chloride,tetrafluoroethylene, chlorotrifluoroethylene, and hexafluoropropylene.

It will be understood that the term “vinyl plastic” includeshomopolymers and copolymers of vinyl monomers. The term “PVC” is meantto include homopolymers of vinyl chloride as well as copolymers of vinylchloride containing up to about 20% by weight of other monovinylidenecompounds copolymerizable therewith, including but not limited to vinylesters, such as vinyl acetate, vinylidene chloride, and alkyl esters ofunsaturated mono- or dicarboxylic acids such as acrylic acid,methacrylic acid, maleic acid and fumaric acid, including vinyl acetate,acrylate esters, and methacrylate esters, and olefins such as ethyleneand propylene, and the like.

Other suitable monomers for use in the thermoplastic polymers of theinvention include, but are not limited to, those disclosed in U.S. Pat.No. 6,875,832 to White et al., the disclosure of which is herebyincorporated by reference, namely allylic monomers, (meth)acrylic acid,(meth)acrylates, (meth)acrylamide, N- and N,N-disubstituted(meth)acrylamides, vinyl esters of carboxylic acids and mixturesthereof.

The thermoplastic polymer of the invention may be a thermoplasticacrylic polymer or copolymer such as describe in, for example, U.S. Pat.No. 4,473,679 to Falk et al and U.S. Pat. No. 4,452,941 to Kishida etal., the disclosures of which are hereby incorporated by reference.Special mention may be made of the acrylate monomers disclosed in U.S.Pat. No. 6,875,832 which include, without limitation, C₁-C₂₀ alkyl(meth)acrylates (including linear or branched alkyls and cycloalkyls)which include, but are not limited to, methyl (meth)acrylate, ethyl(meth)acrylate, propyl (meth)acrylate, isopropyl (meth)acrylate, n-butyl(meth)acrylate, iso-butyl (meth)acrylate, tert-butyl (meth)acrylate,2-ethylhexyl (meth)acrylate, lauryl (meth)acrylate, isobornyl(meth)acrylate, cyclohexyl (meth)acrylate, 3,3,5-trimethylcyclohexyl(meth)acrylate and isocane (meth)acrylate; oxirane functional(meth)acrylates which include, but are not limited to, glycidyl(meth)acrylate, 3,4-epoxycyclohexylmethyl(meth)acrylate, and2-(3,4-epoxycyclohexyl) ethyl(meth)acrylate; hydroxy alkyl(meth)acrylates having from 2 to 4 carbon atoms in the alkyl group whichinclude, but are not limited to, hydroxyethyl (meth)acrylate,hydroxypropyl (meth)acrylate and hydroxybutyl (meth)acrylate. Theresidues may each independently be residues of monomers having more thanone (meth)acryloyl group, such as (meth)acrylic anhydride,diethyleneglycol bis(meth)acrylate, 4,4′-isopropylidenediphenolbis(meth)acrylate (bisphenol A di(meth)acrylate), alkoxylated4,4′-isopropylidenediphenol bis(meth)acrylate, trimethylolpropanetris(meth)acrylate and alkoxylated trimethylolpropanetris(meth)acrylate.

The thermoplastic polymers may also contain maleimide monomers such asmaleimide, N-methyl maleimide, N-iso-propyl maleimide, N-butylmaleimide, N-hexyl maleimide, N-octyl maleimide, N-dodecyl maleimide,N-cyclohexyl maleimide, N-phenyl maleimide, N-2-methyl maleimide,N-2,3-dimethyl phenyl maleimide, N-2,4-dimethyl phenyl maleimide,N-2,3-diethyl phenyl maleimide, N-2,4-diethyl phenyl maleimide,N-2,3-dibutyl phenyl maleimide, N-2,4-dibutyl phenyl maleimide,N-2,6-dimethyl phenyl maleimide, N-2,3-dichlorophenyl maleimide,N-2,4-dichlorophenyl maleimide, N-2,3-dibromophenyl maleimide orN-2,4-dibromophenyl maleimide, and the like as disclosed in U.S. Pat.No. 6,855,769 to Su, the disclosure of which is hereby incorporated byreference.

The thermoplastic polymers may comprise a polyester resin as describedin, for example, U.S. Pat. No. 6,890,991 to Fujimoto et al, thedisclosure of which is hereby incorporated by reference. Such polyesterresins are obtained by the polycondensation reaction of one or moredicarboxylic acids such as, for example, terephthalic acid, isophthalicacid, naphthalenedicarboxylic acid, 4,4′-diphenyldicarboxylic acid,diphenyletherdicarboxylic acid, α, β-bis (4-carboxyphenoxy)ethane,adipic acid, sebacic acid, azelaic acid, decanedicarboxylic acid,dodecanedicarboxylic acid, cyclohexanedicarboxylic acid and dimer acid,or ester-forming derivarives thereof, and one or more glycols such as,for example, ethylene glycol, propylene glycol, butanediol, pentanediol,neopentyl glycol, hexanediol, octanediol, decanediol, cyclohexanedimethanol, hydroquinone, bisphenol A,2,2-bis(4′-hydroxyethoxyphenyl)propane, xylene glycol, polyethyleneether glycol, polytetrafluoroethylene ether glycol, and aliphaticpolyester oligomer having a hydroxyl group at both terminals. Thepolyester resin may be either a homopolyester or a copolyester. Otherexemplary thermoplastic polyesters are disclosed in, for example, U.S.Pat. No. 6,809,151 to Lacroix et al., the disclosure of which is herebyincorporated by reference. Particularly interesting polyesters arepolybutylene terephthalate (PBT) and polyethylene terephthalate (PET).

Suitable thermoplastic polyurethanes materials include those disclosedin U.S. Pat. No. 6,881,856 to Tanaka et al., the disclosure of which ishereby incorporated by reference. As disclosed in that patent,theremoplastic polyurethanes are obtained by reaction ofpolyethercarbonate diols with a diisocyanate and a chain extender, suchas a polyol or polyamine compound, by a polyurethane-producing reaction.The exemplary polyethercarbonate diols, diisocyanates, and chainextenders disclosed in U.S. Pat. No. 6,881,856 are hereby incorporatedby reference.

The thermoplastic polymers of the invention may also comprisethermoplastic polyamides (nylons) such as those disclosed in U.S. Pat.No. 6,870,005 to Lieberman et al., the disclosure of which is herebyincorporated by reference. These thermoplastic polyamides may beprepared by polymerization of, for example, one or more epsilon lactamssuch as caprolactam, pyrrolidone, lauryllactam and aminoundecanoiclactam, or amino acid, or by condensation of dibasic acids and diamines.Exemplary polyamides include polycaprolactam (nylon 6), polylauryllactam(nylon 12), polyhexamethylenedipamide (nylon 6,6),polyhexamethyleneazelamide (nylon 6,9), polyhexamethylenesebacamide(nylon 6,10), polyhexamethyleneisophthalamide (nylon 6,10), thecondensation product of 11-aminoundecanoic acid (nylon 11),polytetramethyleneadipamide (nylon 4,6), polyhexamethyleneazelaamide(nylon 6,9), polyhexamethylenesebacamide (nylon 6,10),polyhexamethylenedodecanediamide (nylon 6,12), andpolydodecanemethylenedodecanamide (nylon 12,12). Other suitable nylonresins are disclosed in, for example, U.S. Pat. No. 6,861,470, thedisclosure of which is hereby incorporated by reference.

Thermoplastic polycarbonate plastics are also well known in the art andinclude, for example, those described in U.S. Pat. No. 5,756,641 toKuhling et al., the disclosure of which is hereby incorporated byreference. Such polycarbonates are formed by transesterification ofaromatic diphenols with carboxylic acid diaryl esters. Exemplarydiphenols include, without limitation, 4,4′-dihydroxydiphenyl,4,4′-dihydroxydiphenyl sulphide, 2,2-bis-(4-hydroxyphenyl)-propane,2,2-bis-(3,5-dimethyl-4-hydroxyphenyl)-propane,2,2-bis-(3,5-dichloro-4-hydroxyphenyl)-propane,2,2-bis-(3,5-dibromo-4-hydroxyphenyl)-propane,1,1-bis-(4-hydroxyphenyl)-cyclohexane, and1,1-bis-(4-hydroxyphenyl)-3,3,5-trimethylcyclohexane. Exemplarycarboxylic acid diesters include without limitation di-C₆-C₂₀-arylesters, such as the diesters of phenol or of alkyl-substituted phenols.Special mention may be made of diphenyl carbonate or dicresyl carbonate.

Particularly interesting polymers according to the invention comprisepolyvinyls, polyacrylates, polyurethanes, polycarbonates, polyesters,polyamides, polyolefins, and combinations thereof. Polyvinyl andpolyolefin polymers are especially interesting polymers according to theinvention.

The foregoing monomers and polymers are provided by way of example onlyand are not intended to limit the scope of the invention. The skilledartisan will recognize that any of the numerous thermoplastic polymersknown in the art are contemplated to be within the scope of the presentinvention.

Alternatively, the plastic component may be a thermosetting plastic suchas, without limitation, epoxy resin, polyester resin, natural rubberssuch as latex, melamine plastics such as Formica®, phenolics such asBakelite, urea-formaldehyde, and the like.

The compositions of the present invention also include as an essentialcomponent an inorganic salt. While it is contemplated that a widevariety of inorganic salts will be useful in the practice of theinvention, it is advantageous to employ a fire extinguishing inorganicsalt. Particular mention may be made of inorganic salts of phosphoricacid, metaphosphoric acid, orthophosphoric acid, pyrophosphoric acid,polyphophoric acid, sulfuric acid, and hydrochloric acid. Ammonium saltsare especially useful. Accordingly, particularly interesting inorganicsalts include but are not limited to ammonium phosphates, such as(NH₄)H₂PO₄ (mono-ammonium phosphate or ammonium phosphate) and(NH₄)₂HPO₄ (di-ammonium phosphate), and ammonium sulfates, including(NH₄)₂SO₄ (ammonium sulfate or di-ammonium sulfate) and (NH₄)HSO₄(ammonium hydrogen sulfate or ammonium bisulfate), and (NH₄)₂Cl. In oneinteresting embodiment, the inorganic salt comprises ammonium sulfates,especially (NH₄)₂SO₄. Combinations of any of the foregoing inorganicsalts are also contemplated to be useful.

The inorganic salt is in particulate form. While it is contemplated thatany size inorganic salt particulate material will be useful in thepractice of the invention, preferred materials will have averageparticle diameters of below about 1 mm. Accordingly, in one embodimentof the invention, the inorganic salt particulate material has an averageparticle size of about 0.001 μm to about 1,000 μm. In anotherembodiment, the inorganic salt particulate material has an averageparticle size of about 0.01 μm to about 300 μm. In particularlyinteresting embodiments, the particle size of the inorganic salt isbetween about 0.1 to about 30 μm, 1 and about 10 μm, and about 5 toabout 8 μm. Further, the invention embraces embodiments within the rangeof 0.001 μm to about 1,000 μm wherein the lower and upper limits areincreased or decreased by intervals of 5 μm, each such sub-range beingan embodiment of the invention.

The particles size distribution of the inorganic salt particulatematerial may be selected by any known method in the art, including theuse of mesh sieves. The particle sizes which will pass through standard(Tyler or BS-410) mesh sizes are well known in the art. Inorganic saltparticulate materials which have an average particle size sufficientlysmall to pass through any of the standard Tyler mesh sizes arecontemplated to be useful in the practice of the present invention.Accordingly, with regard to the standard Tyler mesh sizes, the inventionembraces embodiments having particle sizes of less than about 297, 250,210, 177, 149, 105, 74, 62, 53, 44, 37, 20, 10, and about 5 μm,respectively. Further control over the distribution of particle size isobtainable by passing the material through two sieves of different mesh,as is well known in the art. The skilled artisan will recognize thatvarious permutations of standard mesh sizes can by employed to obtain avariety of particle size ranges, each of which is contemplated to be anembodiment of the invention. Of course, it is also within the skill inthe art to employ non-standard mesh sizes to obtain any desired particlesizes which are larger, smaller, or intermediate to those provided bythe standard Tyler mesh sizes.

Methods for mechanically micronizing particulate matter (i.e., crushing,grinding, and milling) are well known in the art as disclosed in, forexample, U.S. Pat. No. 6,726,133 to Hahn et al and U.S. Pat. No.5,732,894 to Sheahan, the disclosures of which is hereby incorporated byreference. Non-mechanical methods for forming micronized andnanoparticulate materials are also well known in the art, as disclosedin, for example, U.S. Pat. No. 5,874,029 to Subramaniam et al., thedisclosure of which is hereby incorporated by reference. It is withinthe skill in the art to provide inorganic salts in particulate formhaving the particle sizes disclosed herein.

For example, U.S. Patent Application Pub. No. 2002/0065198 to Highsmithet al., which is incorporated herein by reference, discloses a processfor ball milling commercially available ammonium sulfate granules ofapproximately 1 mm average size to produce micronized ammonium sulfateparticles having the particle size profile shown in Table I:

TABLE I Tyler Sieve No. Wt. % Retained 48 Less than 0.1 60 0.3 80 0.4100 0.3 200 18 230 49 400 19 pan 13

The compositions of the invention generally comprise the plastic polymerbetween about 10% and about 80% by weight and comprise the inorganicsalt between about 20% to 80% by weight, with the proviso the sum of theweight % of each component not exceed 100%. In variations of thisembodiment, the lower limit of the weight ranges of inorganic salt maybe at least 26%, 27%, 28%, or at least 29% by weight. The invention alsocontemplates sub-ranges within the foregoing ranges wherein the lowerand/or upper limits are increased or decreased, respectively, byintervals of 5 weight %, each such sub-range being an embodiment of theinvention.

In one embodiment, the compositions comprise the plastic polymer betweenabout 10% and about 60% by weight and comprise the inorganic saltbetween about 30% to 80% by weight. In another embodiment, thecompositions comprise the plastic polymer between about 10% and about50% by weight and the inorganic salt between about 40% to 80% by weight.In another embodiment, the compositions comprise the plastic polymerbetween about 10% and about 40% by weight and the inorganic salt betweenabout 50% to 80% by weight. In a further embodiment, the compositionscomprise the plastic polymer between about 10% and about 30% by weightand the inorganic salt between about 60% to 80% by weight. In an yetanother embodiment, the compositions comprise the plastic polymerbetween about 10% and about 20% by weight and the inorganic salt betweenabout 70% to 80% by weight. The weight ratio of plastic polymer toinorganic salt is typically in the range of about 1:8 to about 5:1,including embodiments of 1:7 to about 4:1, 1:5 to about 3:1, 1:3 toabout 2:1, and 1:2 to about 1:1.

One variant of the plastic-like compositions of the invention comprises:(a) about 10 to about 80% by weight of a plastic polymer; and (b) about10 to about 80% by weight of an inorganic salt having an averageparticle size between about 0.001 and about 300 μm; said compositionhaving a reduced propensity to ignite or smoke in the presence of heator flame as compared to said plastic polymer alone; with the provisothat when the weight of the inorganic salt component is ammonium sulfatecomprising 25% or less by weight of the composition, the plastic-likecomposition is substantially non-intumescent.

It is believed that the compositions of the invention comprise aplurality of inorganic salt particles, such as ammonium sulfate inparticulate form, having any of the average particle sizes set forthabove, held in a homogenous physical unit by a plastic polymeric binder.By “homogenous physical unit” it is meant that the inorganic salt andthe plastic are not readily separable from one another. Unlikeconventional plastics, in which a polymeric material forms a matrixwhich constitutes the bulk of the material, the bulk of the compositionsof the invention may be provided by the inorganic salt. It is believedthat in the present invention, the plastic material serves as a binderto hold the particulate matrix in place and impart flexibility,ductility, and the like, to the compositions.

The compositions of the invention may comprise additives. When present,additives may comprise between about 0.01% and about 35% by weight ofthe composition. In one embodiment, the additives comprises about 20% byweight of the composition.

The additives include all those well known in the art, including but notlimited to, intumescent additives, plasticizers, stabilizers, fillers,blending resins, pigments, and additives, as well known to one skilledin the art. Any plasticizer, stabilizer, filler, or other additive knownin the art may be used in the present invention. Suitable plasticizer,stabilizer, fillers, and other additives, include but are not limitedto, those disclosed in U.S. Pat. No. 6,706,820 to Kumaki, et al., U.S.Pat. No. 5,552,484 to Enomoto, and U.S. Pat. No. 4,042,556 to Yoshinaga,the contents of which are hereby incorporated by reference herein. Theplastics may further comprise U.V. stabilizers, colorants, and impactmodifiers. Additives including, but not limited to, low flammabilityoils such as soybean and corn oils, calcium carbonate, calcium stearate,titanium dioxide, paraffin wax, oxidized PE lubricant, phthalateplasticizers, heat stabilizers, impact modifiers, and intumescentadditives are particularly notable. The plasticizer 2-ethyl hexyldiphenyl (Santicizer® 141, Ferro Corp.) has been found useful in thepractice of the invention. Thinners for processing may also be desirablein some applications.

If desired, blowing agents such as for example, chlorinatedfluorocarbons, HCFCs, butane, isopentane, carbon dioxide, nitrogen,argon, and the like, may also be used to produce foamed products, all inaccordance with well known practice in the art. Methods for makingfoamed plastic are disclosed in, for example, U.S. Pat. Nos. 3,983,296and 4,120,833 to Purvis, et al., U.S. Pat. No. 4,017,657 to Foley, etal., U.S. Pat. No. 4,042,556 to Yoshinaga, U.S. Pat. Nos. 5,391,585 and5,324,461 to Grohman, U.S. Pat. No. 5,686,025 to Martin, U.S. Pat. Nos.5,783,613 and 5,786,399 to Beekman et al., U.S. Pat. Nos. 6,225,365 and6,225,365 to Zerafati, et al., and S. K. Dey et al. “Inert-Gas Extrusionof Rigid PVC Foam” Journal of Vinyl & Additive Technology, March 1996,Vol. 2, No. 1., the contents of which are hereby incorporated byreference herein.

The compositions of the invention may be formed in any techniqueconventional for forming thermoplastics or thermosettings, including,for example, extrusion, injection molding, blow molding, rotomolding,thermoforming, calandering, and compression molding. The materials ofthe invention may be extruded in the same manner as conventionalplastics, as disclosed in, for example, U.S. Pat. No. 6,350,400 toPiotrowski, U.S. Pat. No. 4,322,170 to Papenmeier; U.S. Pat. No.3,983,186 to Eilers, et al., M. J. Stevens, “Extruder Principals andOperation”, Elsevier Applied Science Publishers, New York, N.Y. (1985),and C. Rauwendaal, “Polymer Extrusion”, Hanser Publishers, New York,N.Y. (1986), the contents of which are hereby incorporated by referenceherein. The compositions are suitable for injection molding and thelike. The compositions of the invention may also be formed by rollingunder heat as is also well known in the art.

As evident from the foregoing, the compositions of the invention containfar less polymeric material derived from petroleum than conventionalplastics. For example, conventional compounded PVC has the makeup givenin Table II.

TABLE II Weight Percent Material (based on PVC resin) PVC Resin 100Impact Modifier 5.0 Heat Stabilizer 0.8 Filler (CaCO₃) 10 CalciumStearate 1.4 Processing Aid 0.8 Oxidized PE Lubricant 0.15 Paraffin Wax1.2 TiO₂ 2.0

As shown in Table III, conventional compounded PVC comprisesapproximately 83% by weight polyvinyl chloride polymer, which itselfcomprises 43% by weight petroleum-derived material. Thus, even polymerssuch as PVC, which is generally considered to be a “low-petroleum”content material, contains 0.36 pounds (or 36% by weight) of polymerderived from petroleum for every pound of compounded PVC. In contrast,Table III provides three exemplary low-petroleum content formulations ofthe invention. In each case, the compounded PVC resin is mixed withammonium sulfate and plasticizer in the ratios given.

TABLE III Weight % ammonium Compounded of petroleum- sulfate PlasticizerPVC derived polymeric Sample (wt. %) (wt. %) (wt. %) component 1 60 1921 7.6 2 55 19 26 9.4 3 50 19 31 11.2

Based on the foregoing, the benefits of the present invention as appliedto high petroleum content plastics, such as, for example, polyethyleneand polypropylene, are immediately apparent. The petroleum based contentof such plastics can be reduced by at least about 30%, 35%, 40%, 45%,50%, 55%, 60%, 65%, 70%, 75%, or 80%, each being considered anembodiment of the invention. It is contemplated that even greaterreductions in the petroleum based content of plastic materials areachievable with the present invention.

The compositions of the invention have a reduced propensity to ignite orsmoke in the presence of heat or flame as compared to the plastic bindermaterial alone. This property is believed to arise from the reducedpetroleum content of the materials and the fact that flame retardantinorganic salts, such as ammonium sulfate, release inert gases (i.e.,N₂) upon decomposition with heat. Accordingly, in particularly desirableembodiments, the inorganic salt is a flame retardant inorganic salt. Thecompositions of the invention are substantially non-intumescent, in theabsence of added intumescent material. This does not preclude, however,the addition of minor amounts of intumescent additives such asintumescent catalysts, carbonifics, and/or blowing agents to thecompositions.

EXAMPLE 1 Preparation of Micronized Ammonium Sulfate

Approximately 20 pounds of ammonium sulfate and approximately 15 poundsof glass balls with sizes ranging from 0.5 to 1 inches were placed in astandard cement mixer. The ammonium sulfate was ground for about fourhours. The material was then passed through a 500 Tyler mesh screen.Substantially all of the material passed through the screen indicatingthat the maximum particle size was about 25 μm. This material was usedto make the materials described in the following examples.

EXAMPLE 2

Approximately 60 gm of micronized ammonium sulfate from Example 1 wasmixed with approximately 21 gm of a standard compounded PVC (see TableII) and approximately 19 gm pounds of the 2-ethyl hexyl diphenylplasticizer Santicizer® 141 (Ferro Corp.). The mixture was formed intosheets having a thickness of about 30 mil with twin rollers operating at380° F. for about five minutes, or until homogeneous.

EXAMPLE 3

Approximately 55 gm pounds of micronized ammonium sulfate from Example 1was mixed with approximately 26 gm pounds of a standard compounded PVC(see Table II) and approximately 19 gm pounds of the 2-ethyl hexyldiphenyl plasticizer Santicizer® 141 (Ferro Corp.). The mixture wasformed into sheets having a thickness of about 30 mil with twin rollersoperating at 380° F. for about five minutes, or until homogeneous.

This material was tested for fire retardancy by an independentlaboratory with the Underwriters Laboratories (“UL”) flame testdesignated UL-94. The material received the highest UL-94 rating of V-0.

The material also passed the U.S. Government standard for flammabilityresistance FAR 25.853. That test involves subjecting a panel to edgeburning by a flame maintained at 1550° F. for a period of 60 seconds andrequires that the material be self-extinguishing before 15 seconds andthat it be non-dripping. After subjecting the material to flame for 60seconds, there was no flaming or dripping of the material.

EXAMPLE 4

Approximately 50 gm of micronized ammonium sulfate from Example 1 wasmixed with approximately 31 gm of a standard compounded PVC (see TableII) and approximately 19 gm pounds of the 2-ethyl hexyl diphenylplasticizer Santicizer® 141 (Ferro Corp.). The mixture was formed intosheets having a thickness of about 30 mil with twin rollers operating at380° F. for about five minutes, or until homogeneous.

EXAMPLE 5

Approximately 35 gm of micronized ammonium sulfate from Example 1 wasmixed with approximately 46 gm pounds of a standard compounded PVC (seeTable II) and approximately 19 gm pounds of the 2-ethyl hexyl diphenylplasticizer Santicizer® 141 (Ferro Corp.). The mixture was formed intosheets having a thickness of about 30 mil with twin rollers operating at380° F. for about five minutes, or until homogeneous.

The material also passed the U.S. Government standard for flammabilityresistance FAR 25.853(b). That test involves subjecting a panel to edgeburning by a flame maintained at 1550° F. for a period of 12 seconds andrequires that the material be self-extinguishing before 15 seconds andthat it be non-dripping. After subjecting the material to flame for 12seconds, there was no flaming or dripping of the material.

EXAMPLE 6

This example provides a material according to the invention wherein thepolymeric binder is a thermosetting polymer. 48 parts of polyester resin48 (approximately 4 pounds) was mixed with 52 parts (approximately 4.5pounds) ammonium sulfate from Example 1 in one gallon container. Thecomposition was mixed until homogenous, about 5 minutes, with a drillblade. After mixing, about 900 drops of a methyl ethyl ketone peroxide(MEKP) hardener was added to set the material.

A 24 feet, 30 mil thick coating of this material was subjected to ASTME-84 flame spread and smoke evolution testing. The flame spread indexwas 15 and smoke index was 45. There was no evidence of progressivecombustion after 30 minutes. Thus, the material passed ASTM E-84 with aClass A rating.

It will be understood that the recitation of ranges contained herein areas a matter of convenience only and the inventors are in possession ofevery value intermediate within the ranges. That is, every intermediatevalue or sub-range within a disclosed range should be understood to beinherently disclosed.

The invention having been described by the foregoing description of thepreferred embodiments, it will be understood that the skilled artisanmay make modifications and variations of these embodiments withoutdeparting from the spirit or scope of the invention as set forth in thefollowing claims.

1. A composition comprising: (a) about 10 to about 80% by weight of athermoplastic polymer and (b) about 20 to about 80% by weight of aninorganic salt having an average particle size between about 0.001 andabout 300 μm, wherein the composition has a reduced propensity to igniteor smoke in the presence of heat or flame as compared to thethermoplastic polymer alone, and wherein the composition meets the U.S.Government standard for flammability resistance FAR 25.853(b) and/orpasses the ASTM E-84 test with a Class A rating. 2-6. (canceled)
 7. Thecomposition of claim 1 wherein the thermoplastic polymer comprisespolyethylene.
 8. The composition of claim 1 wherein the thermoplasticpolymer comprises polypropylene.
 9. The composition of claim 1 whereinthe thermoplastic polymer comprises a polyvinyl polymer. 10-12.(canceled)
 13. The composition of claim 1 wherein the inorganic saltcomprises an ammonium salt.
 14. The composition of claim 1 wherein theinorganic salt comprises a salt of sulfuric acid or phosphoric acid. 15.The composition of claim 13 wherein the inorganic salt comprises anammonium salt of sulfuric acid or phosphoric acid.
 16. The compositionof claim 15 wherein the inorganic salt comprises ammonium sulfate. 17.The composition of claim 1 wherein the inorganic salt has an averageparticle size between about 0.01 and about 100 μm. 18-23. (canceled) 24.The composition of claim 1 further comprising one or more additivesselected from the group consisting of plasticizers, stabilizers,fillers, blending resins, pigments, and impact modifiers.
 25. Thecomposition of claim 24 wherein the one or more additives are present inan amount between about 0.05% and about 35% by weight of thecomposition.
 26. A composition comprising: (a) about 10 to about 80% byweight of a thermosetting polymer selected from the group consisting ofpolyesters, epoxy resins, polyester resins, and combinations thereof;(b) about 20 to about 80% by weight of an inorganic salt selected fromthe group consisting of ammonium salts of sulfuric and phosphoric acid;the inorganic salt having an average particle size between about 0.1 andabout 100 μm; and (c) one or more additives selected from the groupconsisting of plasticizers, stabilizers, fillers, blending resins,pigments, and impact modifiers; wherein the composition has a reducedpropensity to ignite or smoke in the presence of heat or flame ascompared to the thermosetting polymer alone, and wherein the compositionmeets the U.S. Government standard for flammability resistance FAR25.853(b) and/or passes the ASTM E-84 test with a Class A rating. 27-42.(canceled)
 43. The composition of claim 26 wherein the one or moreadditives comprises a plasticizer.
 44. The composition of claim 43wherein the plasticizer is present in an amount between about 0.05% andabout 35% by weight of the composition. 45-46. (canceled)
 47. Acomposition comprising a plurality of inorganic salt particles having anaverage particle size between about 0.001 and about 300 μm held in ahomogenous physical unit by a plastic polymeric binder, wherein thecomposition meets the U.S. Government standard for flammabilityresistance FAR 25.853(b) and/or passes the ASTM E-84 test with a Class Arating.
 48. The composition of claim 47 wherein the plastic polymercomprises a thermoplastic polymer. 49-52. (canceled)
 53. The compositionof claim 48 wherein the thermoplastic polymer comprises polyethylene.54. The composition of claim 48 wherein the thermoplastic polymercomprises polypropylene.
 55. (canceled)
 56. The composition of claim 47wherein the plastic polymer comprises a thermosetting polymer.
 57. Thecomposition of claim 56 wherein the thermosetting polymer comprises anepoxy resin.
 58. The composition of claim 56 wherein the thermosettingpolymer comprises a polyester resin.
 59. The composition of claim 47wherein the inorganic salt comprises an ammonium salt.
 60. Thecomposition of claim 47 wherein the inorganic salt comprises a salt ofsulfuric acid or phosphoric acid.
 61. The composition of claim 59wherein the inorganic salt comprises an ammonium salt of sulfuric acidor phosphoric acid.
 62. The composition of claim 61 wherein theinorganic salt comprises ammonium sulfate.
 63. The composition of claim47 wherein the inorganic salt has an average particle size between about0.01 and about 100 μm. 64-69. (canceled)